Field of the Invention
The invention concerns a measuring device for determining the drawer displacement of the tibia with respect to the femur in the leg of a patient.
In the articulating or bracing structure of the knee joint the tibia can, in a so-called drawers movement, be slid toward the front or the back in a drawers-like manner with respect to the femur, wherein the femur condyles can perform a sliding movement upon the facing tibia plateau. Such sliding or translational movements occur, besides during a simple rolling motion, also in the active extension/flexion of the knee joint and again mirror the ligamentary condition thereof. For clinical research of the drawers phenomenon the so-called "Lachmann-Test" is known, in which a researcher grasps the thigh and the calf close to the knee of a patient lying on his back and pulls the shinbone towards the front in the sense of a ventral drawer under application of pressure. This test is subjective and provides no quantitative result with respect to the displacement of a drawer. It is particularly not suited for systematic research of the relationship between the drawer freedom and the condition of the ligamentary complex.